check_availability

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds that it returns busy ranges per calendar (a useful behavioral detail beyond what annotations give), but doesn't mention edge cases like overlapping calendars, timezone handling, or empty-result behavior.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, both informative, no filler. Front-loaded with the core purpose. Could arguably add a usage note but for its length it's efficient and waste-free.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present and full schema parameter coverage plus comprehensive annotations, the description covers the essential purpose adequately. For a read-only check tool that returns busy ranges, this is reasonably complete given the structured fields carry much of the burden.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so all three parameters are documented in the schema itself. The description adds no parameter-specific meaning beyond what the schema provides. Baseline 3 is appropriate when the schema fully covers parameter semantics.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Clear verb+resource ('free/busy status for calendars') with a distinctive scope (returns busy time ranges per calendar) that distinguishes it from sibling event/calendar tools. It doesn't explicitly name an alternative but the check/free-busy concept is distinct from list/get/create/update siblings.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies it's for checking availability, but doesn't explicitly state when to prefer this over list_events (e.g., for scheduling conflicts rather than enumerating event details). No explicit exclusions or alternatives named. The 'free/busy status' context is clear enough to infer usage but not explicitly stated.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.